Segmented After-Air Nozzle for Combustion Penetration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing after-air port configurations in combustion devices face challenges in achieving effective penetration and spreadability of after-air, leading to increased unburned components at furnace outlets, with limitations in reducing unburned components near furnace walls and high costs associated with multiple-stage after-air port configurations.
Innovation Solution
The implementation of a combustion device with primary and secondary after-air nozzles, where the primary after-air nozzle has a larger vertical height than horizontal width, and secondary after-air nozzles with inclination angles that deflect air horizontally, combined with guide vanes and flow rate control mechanisms, to separate and optimize the flow of after-air for improved penetration and spreadability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-stage after-air port configuration is used, then the device complexity is reduced, but the penetration and spreadability of after-air are insufficient leading to increased unburned components
Solution Approach 1:
The after-air port is segmented into multiple nozzles with different orientations: central nozzles for penetration and side nozzles for spreadability. This segmentation allows each nozzle group to perform its specific function independently, achieving both deep penetration and wide distribution of after-air without requiring complex multi-stage configurations.
Solution Approach 2:
Different regions of the after-air port are assigned different functional qualities: the central region provides high-velocity penetrating jets, while the side regions provide low-velocity spreading jets. This local differentiation optimizes the flow characteristics in each region to address specific combustion needs, improving overall combustion efficiency without increasing overall device complexity.
2Productivity
If multiple-stage after-air port configurations are implemented, then unburned components near furnace walls are reduced, but the device complexity and cost increase
Solution Approach 1:
The invention implements a single-stage segmented configuration that replaces complex multi-stage systems. By dividing the after-air port into central and side nozzles within a single stage, the system achieves the same effect of reducing unburned components near furnace walls without requiring multiple sequential stages, thereby simplifying the overall device structure.
Solution Approach 2:
The invention merges the functions of multiple stages into a single stage by combining penetrating and spreading nozzles in one configuration. This integration achieves the cumulative effect of multi-stage systems (both deep penetration and wide distribution) while eliminating the complexity and cost associated with sequential multi-stage arrangements.
3Productivity
If after-air flow rate is increased, then unburned components are reduced, but the flow distribution uniformity deteriorates
Solution Approach 1:
The after-air flow is segmented into different flow paths with different velocities: high-velocity central jets for penetration and low-velocity side jets for spreading. This segmentation allows the system to maintain high overall flow rates for combustion efficiency while ensuring uniform distribution through the velocity differential, preventing flow concentration in specific regions.
Solution Approach 2:
Different velocity qualities are assigned to different flow paths: high velocity in central nozzles for deep penetration and low velocity in side nozzles for wide distribution. This local quality differentiation ensures that high flow rates do not compromise distribution uniformity, as each region receives appropriately velocity-matched flow for its specific combustion needs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces unburned components by ensuring appropriate after-air distribution throughout the furnace, enhancing combustion performance while minimizing costs through optimized nozzle designs and flow control.
Implementation Method 1
a primary after-air nozzle (5) which is provided at a central part in an opening (17) of the after-air port with larger vertical height than horizontal width to supply the primary after-air (1)
Implementation Method 2
one or more pairs of secondary after-air guide vanes (15) which are provided in outlet parts of the secondary after-air nozzles (14) with inclination angles with respect to a central axis (C0) of the after-air port, so as to deflect the secondary after-air (11) right and left in a horizontal direction and supply the same
Implementation Method 3
an after-air port which is capable of low nitrogen oxide (low NOx) combustion having high combustion efficiency
Data Source
AI summary
In accordance with the flow distribution of combustion gas including an unburned portion, an after-air port (AAP) arranged downstream of the two-stage combustion burner can effectively reduce the unburned portion by dividing as appropriate so as to avoid interaction, and by mixing together, two types of after-air having functions of linearity and spreading. As the configuration of this AAP, a primary nozzle for supplying primary after-air and having a vertical height greater than the horizontal width is provided in the center in the opening of the AAP, a secondary nozzle for supplying secondary after-air is provided in the opening outside of the primary nozzle, and one or more secondary after-air guide vanes having a fixed or variable tilt angle relative to the after-air port center axis are provided at the outlet of the said secondary nozzle to deflect and supply the secondary after-air horizontally to the left or right.